Electrical properties of crystalline YSZ films on silicon as alternative gate dielectrics

摘要

Crystalline yttria-stabilized zirconia oxide (YSZ) film was successfully deposited on a silicon wafer without an interfacial amorphous SiO_2 layer The film with equivalent oxide thickness t_eox down to 1.77 nm shows negligible hysteresis and low interface state density, less than 3 × 10~11 cm~-2 eV~-1. The leakage current density for t_eox = 1.77 nm film, 1.5 × 10~-5 A cm~-2 at l V bias voltage, is five orders of magnitude lower than that for SiO_2 with the same equivalent oxide thickness. The results demonstrate that an ultra--thin YSZ film has sufficient resistivity against the formation of an underlying amorphous layer, and can be a promising gate dielectric replacing SiO_2 to reduce the feature size of devices.